A by-election in Clacton will promote Labour's chances of winning the 2015
general election - which would rule out any referendum on Britain's EU
membership

Many people will respect Douglas Carswell’s decision to flip to Ukip and trigger a by-election in Clacton. Politicians who take a risk on the grounds of principle are all too rare. But this particular rebellion is foolish.

We have often said that there are areas of policy that the Government should be swifter to act upon or where they would do better to listen to their Tory instincts rather than passing fashion. But while open debate is to be encouraged, the wisdom of switching to Ukip is hard to fathom. Mr Carswell has made an error of judgment that could damage not only the Conservatives but his own cause. As such, it is both selfish and mistaken.

Take the issue that matters the most to so many on the Right: the future of our relationship with Europe. Mr Carswell claims that the Prime Minister is not negotiating properly with the EU and that he aims to provide “just enough” change to justify campaigning to stay in during the 2017 referendum. He thinks that Mr Cameron is committing a stitch-up.

The Telegraph has argued that Mr Cameron needs to lay out what he wants from the negotiations sooner rather than later and that he must achieve real change to renew the voters’ trust in the European project. But it is no mystery that the Prime Minister ultimately hopes to campaign to remain inside the EU – not nearly as important a point as the fact that he has promised the country the first in/out referendum since 1975. It offers Ukip and Mr Carswell what they profess always to have wanted: an opportunity to vote to quit. But by seceding from the Tories in this dramatic fashion, Mr Carswell threatens the likelihood of that vote ever taking place. If Ukip helps put Ed Miliband in No 10 by splitting the Right, it would advance the cause of a Left-wing Europhile with no such commitment to holding a referendum. As Daniel Hannan, Mr Carswell’s friend and ideological fellow traveller, has stated: “The split in British Euroscepticism is ruinous.” Of course, Mr Carswell is free to follow his heart and do what he thinks is right. But he has done so at the expense of his head.

A by-election at this moment in the political cycle is also a huge distraction from what really matters. And there is much that the UK needs to address. Isil has spread its poison across Iraq and Syria, persecuting religious minorities and threatening the Kurdish homeland. Next week, Nato meets in Wales, and on its agenda will doubtless be the perilous situation in Ukraine. The awful revelations from Rotherham deserve a public inquiry: the abuse of 1,400 children over 16 years, and the terrible neglect by police and social services, demand explanation and the punishment of those involved.

Into that mix could be thrown the subject of immigration. New figures show that the number of immigrants coming to Britain surged to 560,000 last year. In addition, the terrorism threat level has just been raised – to “severe”.

We are not saying that Tory MPs should not feel able to contribute to the debate about these matters or to disagree strongly with the positions taken by the Government. But how will a costly by-election in Clacton help the country move forward?

Again, the only thing it will help is Labour’s chances of winning the next election. If Mr Carswell is victorious in Clacton then, presumably, Ukip hopes that it will prove to its Euro election voters that it can win parliamentary seats and that they should stick with it through to 2015. This is likely to cost the Tories MPs, with the result that Mr Miliband might slip into No 10 without necessarily winning more votes than

Mr Cameron. What would that mean for Mr Carswell’s laudable small state agenda? It would mean price-fixing for energy and rents, the prospect of partial rail nationalisation, higher taxes, a reversal of some of Michael Gove’s excellent education reforms and a return to the failed economics of the Blair/Brown years. And, to repeat for added emphasis, no referendum on Europe. It would represent a reversal of five years’ hard work – a tragedy for the country brought about less by the political strengths of the Left than the maddening self-laceration of parts of the Right.

Another irony is that while Mr Carswell has a long and admirable record of campaigning for greater local democracy, his defection has led to accusations of candidate fixing. Roger Lord, the man chosen to fight Clacton in 2015, tells us that he feels entitled to run for Ukip in this by-election and cannot understand why Mr Carswell presumes he will replace him. The former Tory now stands accused of being parachuted into his own constituency. Voters in the by-election would do well to stick with the Conservatives, and with a candidate who will stay loyal to the party and the pledges he makes in the campaign.

It is rumoured that other Tories are thinking of switching to Ukip, too – that they are waiting to see what happens to Mr Carswell. They ought to put the idea out of their heads and focus on helping Mr Cameron win a majority in 2015, free himself from the Coalition and put traditional, growth-spurring Tory policies into practice. Anyone who threatens that ambition doesn’t just risk rocking the boat. They risk tipping it over and drowning conservatism with it.